HOW STUFF WORKS
QUIZZES

FOLLOW US
The Ultimate Coral Reef Quiz
by Staff
For an underwater tourist, whether in a wetsuit or in front of a TV, a major attraction is a coral reef, an amazing ecosystem inhabited by myriad colorful marine creatures. Unfortunately, coral reefs are in danger of disappearing unless immediate steps are taken to preserve this natural wonder. Take this quiz to learn more about what needs to be done.

What is a coral reef?

  • It is a fossilized remnant of rainforests that were once above the water.
  • It is a foundation of stone with different types of marine growth covering it.
  • It is made from stony corals and discharged limestone skeletons.

How long will it be until an estimated 70 percent of coral reefs disappear?

  • 20 years
  • 40 years
  • 60 years

Does a coral reef contribute to the environment?

  • It buffets the coastal areas from storms and powerful waves.
  • It benefits the tourist trade.
  • They protect smaller fish from sharks and other predators.

How big is a single coral?

  • 15 millimeters
  • 10 millimeters
  • 3 millimeters

What is a polyp?

  • a protrusion from the reef
  • a single coral
  • digestive gland of the coral

Is the coral a plant?

  • It's a living creature.
  • It is a sophisticated fish-eating plant.
  • It defies precise definition because of its unique nature.

What does sessile mean?

  • It's a creature that lies in wait for prey.
  • It is an asexual creature.
  • It means fixed in place.

Why did scientists originally think corals were plants?

  • They had never seen a living creature attached to a substratum.
  • The tentacles of the coral look like tree branches.
  • There was no evidence of a breathing mechanism necessary to sustain life.

What is common to the jellyfish, sea anemone and the coral?

  • carnivorous
  • all are protected species
  • all exist exclusively in tropical waters

Since it cannot move from place to place, how does the coral hunt for prey?

  • The coral emits secretions that attract marine life which it swallows when in range.
  • The tentacles send out an electric charge paralyzing small fish.
  • Its tentacles wait until something small and tasty brushes past.

Why could you consider a coral a half-plant?

  • Algae living in he coral's cell walls provide products the coral turns into nutrients.
  • The coral is implanted in the reef.
  • The tentacles are identical to parts of certain plants that entrap insects.

What do algae gain from coral?

  • The algae feed on scraps of undigested fish bones.
  • The coral supplies carbon, nitrates and phosphates.
  • The algae feed on plant growths that irritate the coral.

What is this useful arrangement known as?

  • dependency
  • mutually assured destruction
  • symbiosis

What is the substance the polyps secrete?

  • calcium carbonate
  • phosphate
  • sodium chloride

To what use is this substance put?

  • provides toxins for the tentacles
  • food for other marine life
  • a protective chamber or shell

How many polyps can be found in a single branching coral?

  • hundreds
  • thousands
  • tens of thousands

When polyps join together into a colony what happens to them?

  • Each polyp continues to operate individually from a common location.
  • They form larger working groups competing with the other groups.
  • They all work together as a single organism.

Do polyps reproduce?

  • by producing identical clones (asexually)
  • by sending out eggs or sperm (sexually)
  • by dividing thereby producing identical clones (asexually) and by sending out eggs or sperm (sexually)

How is a new colony formed?

  • Strong underwater currents cause corals to break away and drift to a new location.
  • Newly created polyps settle downwards until they reach a hard surface.
  • Large fish break off pieces of coral which they dump when can't digest it.

What do coral reefs need to survive and flourish?

  • sunlight and warm salty water
  • cool water rich in nutrients
  • fewer fish nibbling away at the reef